This invention is an improvement upon the apparatus described and clamed in U.S. Pat. No. 4,014,635 which issued Mar. 29, 1977 to Karl Kristian Kobs Kroyer.
In additon to the Kroyer patent, the following patents are believed to be pertinent.
U.S. Pat. No. 2,165,280 issued July 11, 1939 to G. M. Lannan for a "Method and Apparatus for Forming a Fibrous Mat". The apparatus is particularly adapted for the production of fiberglass filters for use in air conditioners, and the like. The glass fibers are deposited upon a reticulated belt which passes through the bottom of the machine. U.S. Pat. No. 3,071,822 issued Jan. 8, 1963 to J. G. Meiler for a "Method and Apparatus for Forming a Mat". The patent teaches the use of two or more air laying units in side-by-side configuration for depositing fine and coarse fibers onto the belt to form a mat. The belt is a foraminous belt which has suction chambers immediately below the belt to hold the fibers on the belt.
U.S. Pat. No. 3,080,617 issued Mar. 12, 1963 to K. G. Lytton for a "Fiber Proportioning, Blending, and Preparation Method, System and Apparatus". The disclosed apparatus is directed toward the mixing of different textile fibers into a homogeneous mass. Different yarn is deposited from dispensers onto a common belt.
U.S. Pat. No. 3,598,680 issued Aug. 10, 1971 to C. A. Lee for a "Tandem Air Former". The apparatus is directed to air laying fibrous material at a first station and then air laying additional fibrous material at a second station downstream from the first station to overlap at least partially the fibrous material deposited at the first station. A pressure differential is maintained across the web to hold the web onto the carrier belt or wire.
U.S. Pat. No. 3,645,457 issued Feb. 29, 1972 to G. Berndt, et al for an "Apparatus for Depositing Comminuted Materials Upon Traveling Conveying Means". The Apparatus is essentially a blower for blowing wood chips onto a belt for building up a structure of coarse chips in the center and fine chips on the outer layers, the resulting composite structure being sutiable for the production of fiberboards.
U.S. Pat. No. 3,581,706 pertains to a Kroyer-like apparatus for distributing fibers onto a foraminous wire belt.
U.S. Pat. No. 3,825,381 issued July 23, 1974 to C. E. Dunning, et al for "Apparatus for Forming Airlaid Webs". The apparatus is directed to air laying wood fiber webs onto a high speed foraminous wire or carrier, then wetting it before it is transferred for further processing.
U.S. Pat. No. 3,886,629 issued June 3, 1975 to S. Nakai, et al for an "Apparatus for Producing Fibrous Mats". The apparatus is directed toward grinding or disintegrating pulp to produce pulp fibers which are then deposited onto a moving wire.
Austrian Pat. No. 220,466 issued Aug. 15, 1961 to the Weyerhaeuser Timber Company pertains to the consecutive depositing of wood chips onto a foraminous wire belt having a suction chamber underneath. The belt travels from depositing head to depositing head in a common tunnel.
The Kroyer apparatus of U.S. Pat. No. 4,014,635 uses a fiber distributor which has a housing, a plane-surface perforated bottom wall, and impellers which are mounted for rotation about vertical axes. The impellers are mounted just above the plane-surface bottom wall. Means are also provided in the housing for receiving fibers and additional means are provided for removing fibers of excess size.
Further to the Kroyer patent, a foraminous wire belt moves below the bottom wall of the housing, and a suction box is located below the wire belt. At the front and back walls of the housing, at the points of entrance and exiting of the wire belt, two rollers are positioned to act as sealing members to avoid the intake of substantial amounts of false air. The rollers are mounted so that small gaps are formed between the lower edges of the housing and the roller surfaces. The rollers may be positively driven or may rotate on the wire belt. Typically paper pulp is introduced into the fiber distributor housing after having been disintegrated in, for example, a hammer mill. The rotating impellers drive the fine particles through the perforated bottom wall onto the moving wire belt.
When two Kroyer fiber distributors deliver fibers sequentially to the same wire belt, the fibers typically spring up and fluff on the belt in the region between the Kroyer distributors.
This invention is related to a patent application, filed concurrently herewith by Frederic N. Miller entitled MULTIPLE DISTRIBUTOR HEADS FOR LAYING DRIED FIBERS, Ser. No. 915,865, which pertains to two side-by-side Kroyer type machines, without space therebetween and delivering fibers into a common tunnel onto a foraminous belt.